Heterogeneous blends of polycarbonate with either polyolefin or modified polyolefin resins are well known and used in a variety of applications because inter alia of their superior impact strength compared to unblended polycarbonate resins. For example, heterogeneous blends of polycarbonate and a variety of polyolefin resins are described in U.S. Pat. No. 3,431,224 to Kenneth B. Goldblum. As described therein, admixtures of polycarbonate including at least one member of the class consisting of polyethylene, polypropylene, polyisobutylene, a copolymer of ethylene and an alkyl acrylate, a copolymer of ethylene and propylene, a cellulose ester, a polyamide, a polyvinyl acetal, an alkyl cellulose ether, and a polyurethane elastomer exhibit improved solvent resistance and impact strength.
Nevertheless the heterogeneous blends of polycarbonate and polyolefin resins previously known are difficult to use for molding articles requiring multiple gates. Because the polycarbonate and polyolefin polymers mentioned above are incompatible, molded articles made therefrom using multiple gates frequently failed, often along their weld lines. In addition, prior products made from heterogeneous blends of polycarbonate and polyolefin resins exhibit delamination rendering them unsuitable for many uses.